function form_onsubmit(){
	var filter=/^[a-zA-Z0-9_~!@#$%^&*()]{6,20}$/;
	if (!filter.test(document.form.username.value)) { 
                alert("请输入用户名"); 
                document.form.username.focus();
                return (false); 
                }
	if (!filter.test(document.form.password.value)) { 
                alert("请输入密码"); 
                document.form.password.focus();
                return (false); 
                }
	var filter=/^\d{4,4}$/;
	if (!filter.test(document.form.passcode.value))
	{
		alert("验证码必须要填写！");
		document.form.passcode.focus();
		return false;
	}
}
function repwd(){
location.href="repwd.asp";
}